At 11:55 AM 9/11/97 -0700, you wrote:
>On a perfboard prototype I'm working on, I'm having startup problems. Of
>my bag of 16C74A/JW chips, only one or two of them like to work. If I put
>in a real low-speed crystal instead of the 20MHz it's supposed to run at,
>I can sometimes coax it to run.
Are the configuration word bits 1 and 0 set to '10' for HS oscillator mode?

>Putting a scope on the crystal pins verifies that the oscillator is
>running, but I suspect it's burping or slow getting up to speed or
>something.
What size capacitors do you have from the crystal leads to ground?
The oscillator may be starting only when your probe capacitance is added to
the circuit.


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Lynn Richardson - Design Eng.|WA0ZNL            |Progress Instruments, Inc.
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